What is unknown in skeletal muscles?

Skeletal muscles are a highly specialized animal tissue whose basic function is the contraction, which leads into animal movement. One of the types of skeletal muscles are trunk (myotomal) muscles, which in vertebrates belong to the oldest phylogenetically group of muscles. The comparative studies of myotomal myogenesis have shown that these muscles, despite a similar structure plan and under the control of the same genetic factors, may differentiate differently in individual species of vertebrates (both in model and non-model species). The understanding of the skeletal muscle development mechanisms seem to be a precondition for understanding the muscle tissue diseases observed in humans. This paper summarizes the current knowledge on the skeletal muscles differentiation in animals, pathological states of muscles caused by mutations in the genes of structural and metabolic proteins.